Marinate chicken with fish sauce for at least 15 minutes. Heat oil in large pot, saute onion, garlic, ginger and turmeric for 5 minutes. Stir in chicken and chili flakes. Cover and cook over medium-low heat for 10 minutes. Stir occasionally to prevent chicken sticking to pot. Meanwhile, add chickpea flour to water and whisk to remove lumps
Add chicken stock to the pan and bring to the boil. Reduce heat, cover and simmer for a further 10 minutes and the chicken is cooked through. Add coconut milk and continue to simmer for another 10 minutes.Stir in chickpea flour paste until the soup thickens slightly
Arrange each garnishing item on a separate plate on the table around a central bowl of chicken and coconut chickpeas soup. To serve, take a portion of fresh noodles and a generous helping of soup, add a little of each garnishing (a dash of fish sauce if desired)